When building any kind of software, writing the code is only half the battle. Making sure that code doesn't break when a user clicks a button is the other half! Software testing is the safety net that prevents bugs from making it to production and ruining the user experience.

Broadly speaking, software testing is divided into two execution methods: Manual Testing (human testers interacting with the software) and Automated Testing (scripts running tests automatically). However, when we look at what is being tested, the field breaks down into two main categories: Functional and Non-Functional testing.

Functional Testing

Functional testing answers a simple question: Does the software do what it is supposed to do? It tests the features and operational behavior of the product against the business requirements.

Unit Testing:

The most granular level of testing. Developers test individual functions, methods, or classes to ensure each isolated piece of code works perfectly on its own.

Integration Testing:

Once individual units are built, they are combined. This phase tests the data flow and communication between those combined modules to ensure they play nicely together.

System Testing:

This evaluates the complete, fully integrated software product. It tests the system as a whole to verify it meets the specified requirements.

Acceptance Testing (UAT):

The final hurdle before launch. End-users or clients test the software in a real-world scenario to confirm it solves their problems and is ready for release.

Regression Testing:

Every time you add a new feature or fix a bug, you run regression tests to ensure the new code didn't accidentally break existing, working features.

Non-Functional Testing

Non-functional testing answers a different question: How well does the system perform? It evaluates aspects like speed, scalability, security, and user experience rather than specific features.

Performance Testing:

Checks how the system behaves under different workloads. It ensures the app doesn't crash or slow down to a crawl when a thousand people log in at once.

Security Testing:

Actively looks for vulnerabilities, loopholes, and weaknesses in the system to ensure user data is protected against malicious attacks.

Usability Testing:

Evaluates how intuitive and user-friendly the software is. If users can't figure out how to navigate the app, it fails this test.

Compatibility Testing:

Ensures the software runs correctly across different web browsers, operating systems, and hardware devices (e.g., mobile vs. desktop).